Control for a reciprocating fluid motor

ABSTRACT

A control for a reciprocating fluid motor in which a sliding valve is moved back and forth by a two-piece drive sleeve of resilient material. The drive sleeve comprises a slotted tubular member adapted to be radially compressed to receive the second piece, a nut having a part fitting into the slot to avoid accidental disassembly. The nut and an enlarged portion of the tubular piece work on opposite sides of the slide valve.

United States Patent Passaggio 51 May 23, 1972 CONTROL FOR A RECIPROCATING FLUID MOTOR Charles Po, Cheshire, Conn.

Scovill Manufacturing Company, Waterbury, Conn.

Filed: Sept. 21, 1970 Appl. No.: 73,987

Inventor:

Assignee:

US. Cl ..137/625.69, 91/337, 251/75 Int. Cl 1 ..FOll 31/08, Fl6k 31/56 Field of Search ..91/337; l37/625.69; 285/33;

24/230 F, 230 SC, 201 S References Cited UNITED STATES PATENTS 5/1955 Schweisthal ..9l/337X 2/1967 Newcomb ..285/33X 3,372,439 3/1968 Schmid ..24/230 SC 3,548,717 12/1970 Passaggio ..91/337 FOREIGN PATENTS OR APPLICATIONS 759,653 5/ 1967 Canada ..24/230 F Primary ExaminerMartin P. Schwadron Assistant Examinerlrwin C. Cohen Attorney-Dallett l-Ioopes [57] ABSTRACT A control for a reciprocating fluid motor in which a sliding valve is moved back and forth by a two-piece drive sleeve of resilient material. The drive sleeve comprises a slotted tubular member adapted to be radially compressed to receive the second piece, a nut having a part fitting into the slot to avoid accidental disassembly. The nut and an enlarged portion of the tubular piece work on opposite sides of the slide valve.

2Clains,6l)rawingflgures PATENTED MAY 2 3 I972 SHEET 1 OF INVENTOR Charles Pass ggio 'BYDMAC QAL ATTORNEY PATENTEDMAY23|972 SHEET 2 0F 2 Ila 4 I \I w Fig. 6

l-NVENTOR Charles P assaggw BYEWW ATTORNEY CONTROL FOR A RECIPROCATING FLUID MOTOR This invention relates to a control for a reciprocating fluid motor. More specifically, this invention relates to a reciprocating sliding valve driven by a control rod of a reciprocating motor through a drive sleeve comprising elements of interfitting shapes and which cannot accidentally become disassembled.

My own patent application Ser. No. 833,485, filed June 16, 1969, now U.S. Pat. No. 3,548,717 relates to a reciprocating pump control which has many advantages over the prior art. The present invention may be regarded as an improvement over the earlier structure in that it is cheaper to make, easier to assemble and disassemble, and is long-lasting and economical to produce.

Other objects of the invention will be apparent to one skilled in the art after reviewing the following specification and drawings disclosing a non-limiting assembly embodying the invention. In the drawings:

FIG. 1 is an exploded view of a control assembly embodying my invention;

FIG. 2 is a center-line sectional view reduced in size showing my control assembly in a motor housing;

FIG. 3 is a fragmentary sectional view along the center line showing the control in the position shown in FIG. 2 but in further section;

FIG. 4 is a sectional view similar to FIG. 3 but showing the control rod having pulled down the control assembly;

FIG. 5 is a sectional view taken on the line 5-5 of FIG. 3; and

FIG. 6 is a sectional view showing in detail a lower portion of the drive sleeve assembly.

Referring more specifically to the drawings, a pump having control means embodying the invention is designated 10 in FIG. 2. It comprises an upper housing 12 and a lower housing 14 having the rim of a diaphragm I6 clamped therebetween. From the center of the diaphragm, a drive rod 18 connects piston means 20 operable in a chamber in the lower part of the housing 14 for pumping fluids.

A control rod 22 extends upward from the center of the diaphragm I6 and into a valve housing portion 24. A cylindrical cavity is formed in the housing portion and lined with a tubular liner 26. A vacuum supply port 28 meets an opening 30 in the liner and ports 32 and 34 in the liner on opposite sides of the opening 30 connect respectively to the opposite sides of the diaphragm chamber by passage means not shown.

Reciprocal in the tubular liner 26 is a tubular valve member 36. Preferably, the sliding valve member is of a structure comparable to that shown in my application Ser. No. 884,209, filed Dec. II, 1969, now U.S. Pat. No. 3,610,285.

Disposed intermediate the control rod 22 and the tubular valve member 36 is a drive sleeve 38 which extends upward and is formed at its upper end with a pair of peripheral grooves 40 and 42. The valve housing portion 24 is formed with an annular recess 44 receiving an annular garter spring 46. As shown (FIG. 2), the garter spring 46 resiliently and compressively engages alternately in the two grooves 40 and 42 depending on whether the drive sleeve 38 is in an up or down position.

Air filter means 48 are mounted at the other end of the control means housing 24 for supplying clean air to the control means and the ports 32 and 34 as they are alternately vented.

An essential characteristic of the invention relates to the structure of the drive sleeve 38. Preferably, the drive sleeve is molded of a resilient plastic such as nylon. It comprises (FIG. 1) the upper sleeve portion 38a and the nut 38b. Internally the sleeve is formed with a downwardly facing annular shoulder 39. The lower end of the upper sleeve portion 38a is notched out on opposite sides and slotted as at 50, 51, to present opposite legs 52. The portion 38a is formed with an upper annular flange 53 and a lower flange 54 which may have a tapered periphery 55 to provide a latch.

The upper end of the control rod 22 is reduced in diameter as at 56 and receives a head 58. Disposed on the reduced portion 56 between the shoulder at the reduction and the head are a pair of bushings 60 and 62 with a spring 64, under compression, holding the bushings apart.

The valve member 36 is formed with an arcuate face 70 having a rectangular recess 72. The arcuate face 70 complements the curve of the inside surface of the liner 26. A boss or curb 74 is formed on the valve member and reciprocates in the slot 76 in the liner 26 to keep the valve member oriented so that face 70 is always aligned with the ports 30, 32 and 34. The curb 74 is formed with a track 78 (FIG. 3) and a springpressed ball 80 engages therein to limit the stroke of the valve member.

In assembly, the upper end of the control rod first receives the nut 38b. The bushings 60 and 62 and spring 64 are then mounted on the reduced end of the control rod and head 58 is secured thereon. Then, with the valve element 36 mounted on the narrower lower end of the upper sleeve 38a, that combination is brought down over the upper end until the top of the bushing 62 engages the shoulder 39. The legs 52 are then cammed inward to reduce their diameter as the periphery 55 engages chamfers 57 of the nut 38b. After passage of the nut 38b over the latch, legs 52 snap outward and inward lugs 84 fit into the notches at 50 and thereby block the accidental compression of legs 52 and disassembly of the combination. The upper ends of lugs 84 fit against the lower face of the bushing 60.

With the garter spring disposed in the annular recess 44, the assembly is brought down until the spring engages in one of the grooves 40 and 42.

Thereafter, as the diaphragm moves up and down, control rod 22 acting through drive sleeve 38 will move the valve member 36 alternately to the two positions connecting the central port 30 with either port 32 or port 34 communicating the suction of supply 28 to alternate sides of the diaphragm and venting the other side through the uncovered port 32, 34. The action of the spring 64, as the control rod 22 moves, builds up pressure against the garter spring 46 to ultimately move the drive sleeve and valve member in a snap action to its next position. The flange 53 and the nut 38b comprise the opposite drive faces of the sleeve 38 against the upper and lower ends of valve member 36. The relationship of the parts and lost motion portions may be as described in my first application mentioned above, Ser. No. 833,485.

The present invention may be defined by the following claim language:

I claim:

1. A control assembly for a reciprocating fluid motor having a control rod with outward means adjacent its end and reciprocating with the motor shaft, the assembly comprising a. a valve housing having longitudinally aligned spaced ports into a central chamber enclosing the rod;

b. a tubular sliding valve member reciprocal in said chamber to alternately connect one of the ports with other ports leading respectively to opposite sides of the motor, the control rod extending inside the tubular valve member;

c. a drive sleeve sub-assembly disposed inside the valve member and adapted to receive the control rod, the subassembly comprising a pair of tubular parts one of which is of resilient material and is slotted to provide a radially compressible zone with outward latch means, the zone receiving onto it in snap installation over the latch means the other part to hold it on the first part, the other part having an inward lug which fits into said slot, the two parts having opposed spaced radial outward surfaces to engage respectively the opposite ends of the valve member, and inward means adapted to be engaged by the outward means on the control rod, the drive sleeve also carrying closely spaced depressions, and spring detent means in the housing cooperating with said depressions for selectively biasing the drive sleeve in one of two positions.

2. A control assembly as claimed in claim 1 wherein the drive sleeve assembly is molded of resilient plastic. 

1. A control assembly for a reciprocating fluid motor having a control rod with outward means adjacent its end and reciprocating with the motor shaft, the assembly comprising a. a valve housing having longitudinally aligned spaced ports into a central chamber enclosing the rod; b. a tubular sliding valve member reciprocal in said chamber to alternaTely connect one of the ports with other ports leading respectively to opposite sides of the motor, the control rod extending inside the tubular valve member; c. a drive sleeve sub-assembly disposed inside the valve member and adapted to receive the control rod, the subassembly comprising a pair of tubular parts one of which is of resilient material and is slotted to provide a radially compressible zone with outward latch means, the zone receiving onto it in snap installation over the latch means the other part to hold it on the first part, the other part having an inward lug which fits into said slot, the two parts having opposed spaced radial outward surfaces to engage respectively the opposite ends of the valve member, and inward means adapted to be engaged by the outward means on the control rod, the drive sleeve also carrying closely spaced depressions, and spring detent means in the housing cooperating with said depressions for selectively biasing the drive sleeve in one of two positions.
 2. A control assembly as claimed in claim 1 wherein the drive sleeve assembly is molded of resilient plastic. 